Intramuscular myxoma of the cervical paraspinal muscle

Abstract

Myxoma is a neoplasm of mesenchymal origin composed of undifferentiated stellate cells in a myxoid stroma. This tumor can develop in a variety of locations. Myxomas that arise from skeletal muscles are called intramuscular myxomas. They usually occur in large skeletal muscles. Only ten cases of these benign tumors involving the neck muscles were reported in literature. Of them, only three were located at the paraspinal muscles. A 64-year-old woman presented with occipital and neck pain over 5 years noted an expansive painful lesion located at posterior cervical region with progressive volume increase in the last 12 months. Image exams revealed a large mass located in the left posterior region of the neck in contact with the C2, C3 and C4 laminae with no invasion of the vertebrae. Tumor total removal was performed through normal muscle margins and the vertebral periosteum was scraped. The tumor was encapsulated, lobulated with a gray-white appearance. The histological examination yielded the diagnosis of intramuscular myxoma. Follow-up at 1 year showed complete resolution of preoperative symptoms and no evidence of local recurrence. In conclusion, although rare, intramuscular myxoma should be included in differential diagnosis of cervical paraspinal tumors. We reported the fourth case of intramuscular myxoma in the paraspinal musculature of the neck. Despite its benign characteristics, local recurrence was reported after subtotal resection. Tumor total removal should be the goal of surgery.

Fig. 1

Clinical appearance of the posterior cervical mass reveals a 6 × 6-cm fixed mass in the left posterior aspect of the neck

Fig. 2

Cervical CT scan shows a septated, well-defined and hypodense mass in the left posterior neck. The mass does not enhance with intravenous contrast medium (a). Sagittal and axial T1-weighted MRI shows an intermediate to low signal (b) and the T2-weighted shows an increased signal (c) in the septaded cystic-looking mass

Fig. 3

Intraoperative aspect of the tumor, which was encapsuleted with good cleavage plan (a). Tumor total removal was performed through normal muscle margins and the vertebral periosteum was scraped (b). Macroscopically cut surface of specimen is ovoid, graywish and gelatinous (c)

Fig. 4

Histopathologic views of the intramuscular myxoma. a Photomicrography shows the capsulae of the tumor (purple set) (hematoxylin–eosin; ×4). b Low magnification appearance of the tumor characterized by a paucity of cells, abundance of mucoid material, and almost complete absence of vascular structures (hematoxylin–eosin; ×10). c Photomicrography at higher magnification reveals a myxoid stroma sparsely populated by small spindle shape cells and stellate cells without nuclear atypia and fibers (hematoxylin–eosin; ×40). d Low magnification show the tumor (purple set) surrounded by normal skeletal muscle (green set) (hematoxylin–eosin; ×4)